Temperature relay



Oct. 16, 1923.

N. K. ANDERSEN TEMPERATURE RELAY Filed April 18. 1919 INVENTOR N/e/s KAnde/usen.

ATTORNEY X WITNESSES:

Patented Oct. 16, 1923.

UNITED STATES PATENT OFFICE.

NIELS K. ANDERSEN, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VAN IA.

TEMPERATURE RELAY.

Application filed April 18, 1919. Serial No. 291,152.

To all whom it may concern:

Be it known that I, NIELs K. ANnERsnN,

a subject of.the King of Denmark, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Temperature Relays, of which the following is a specification.

My invention relates to relays and particularly to temperature-responsive relays.

One object of my invention is to provide a. temperature-responsive relay that shall have means for rendering the operation thereof independent of changes in temperature of the ambient air.

Another object of my invention is to provide a device of the above indicated character that shall be effective in its operation and inexpensive to construct.

In practicing my invention, I provide a capillary tube having abody of mercury or other expansible substance disposed intermediate the ends thereof and located in definite space relation to a contact member mounted in the walls of the tube. lower portion of the tube isprovided with air or air and mercury which shall be responsive to changes in the temperature of the surrounding air but not responsive to 30 a heating coil that is used to influence the expansion of the intermediate body of mercury. lVith this arrangement, changes in the temperature of the surrounding air cause the expansion and contraction of the mercury and air and thus change the position of the intermediate body of mercury in such way that the lower end thereof will nothe moved and so that it will expand in one direction only, in accordance with the temperature of the heating coil surrounding the same. p In the accompanying drawings, Fig. 1 is a diagrammatic view of a thermal relay embodying my invention, and 2 is a diagrammatic view of another form of thermal relay embodying my invention.

The relay shown in Fig. 1 comprises a capillary tube 1 having a mercury reservoir 2 in the lower portion thereof. a body of mercury 3 disposed intermediate the ends of the tube 1, and a Winding 4 that is adapted to heat the mercury 3 in accordance with the current traversing a device (not shown) that is to be protected. Contact members 5 are provided for controlling The closing casing 15 therefor protective devices (not shown) when the mercury 3 is heated to a predetermined degree.

- A body of air 6 is disposed above the mercury 3 and a body of air 7 is disposed between the mercury 3 and a body of mercury 8 at the bottom of the tube. The relative proportions of the various bodies of air and 'of mercury are such that any changes in the temperature of the ambient air will cause the bodies of air 6 and 7 and the body of mercury 8 to tend to expand and contract and thus so shift the position of the body of mercury 3 that it is not responsive in. its downward expansion to the changes in the temperature of the ambient air. When the winding 4 is energized, the mercury 3 will expand in accordance with the current traversing the winding to bridge the contact members 5 to complete a protective circuit (not shown).

In Fig. 2 of the drawings, an enclose capillary tube 9 is provided with a reservoir 10 intermediate the ends thereof in which is disposed mercury 11 or other suitable expansible material. Air spaces 12 and 13 areprovided in the respective ends of the tube 9, and a. winding 14 and an ensurround that portion of the tube in which the mercury 11 is located. Contact members 16 are provided for controlling a protective circuit (not shown). The mercury 11 occupies a predetermined volume of the tube 9 and a. predetermined contact members 16. With this form of device, it is only necessary to provide one body of mercury because pressure of the air 13 is relatively greater than that of the air 12 by reason of the weight of the mercury 11'and thus the two bodies of air 12 and 153 may be adjusted to so shift the position of the body of mercury 11, when the temperature of the surrounding air changes, that the mercury 11 will expand only in accordance with the current traversing the Windmg 14.

My invention is not limited to the specific structure illustrated, as it may be variously modified without departing from the spirit and scope of the invention, as set forth in the appended claims.

I claim as my invention:

1. A thermometer comprising a capillary tube, a body of mercury intermediately disposition with regard to the posed therein, means for heating the mercury only and means for preventing the position of the lower end of the body of mercury from being influenced by the temperature of the ambient air.

2. A thermometer comprising a capillary tube, a body of mercury therein, electrical means for heating the mercury only to cause the same to indicate temperature in accordance with the heating effect of the electrical means, said mercury being so positioned between air spaces within the tube that the effect of change in the temperature of the ambient air is neutralized.

3. A thermometer comprising a capillary tube,'a body of mercury therein, electrical -nieans for heating the mercury only to cause the same to indicate temperature in accordance with the heating effect of the electrical means, said mercury being positioned between tWo bodies of air for neutralizing the effect that a change in the temperature of the ambient air may produce in the mercury.

4. A thermal relay comprising a capillary tube, contact members therein, an expansible conducting body disposed in an intermediate portion of the tube and means for heating the conducting body to effect engagement with the contact members, such engagement being efi'ected only in response to the heating of said heating means.

5. A thermal relay comprising a tubular member, an expansible body disposed in an intern'iediate portion of the tube, means for heating the expansible body and means for neutralizing the expansion of said expansible body caused by change in the temperature of the ambient air.

6. A thermal device comprising an enclosed tube, a body of mercury disposed intermediate the ends of the tube and a body of air disposed at each end of the tube to prevent the mercury from responding, in a predetermined direction, to changes in the temperature of the ambient air.

In testimony whereof, I have hereunto subscribed my name this 31st day of March, 1919.

NIELS K. ANDERSEN. 

